Compact oxygen concentrator



FIG. 1 is a three-quarter elevational or perspective view taken from the front of a compact oxygen concentrator embodying my new design;

FIG. 2 is a view thereof similar to FIG. 1 taken from the rear.

FIG. 3 is a side elevational view thereof, the opposite side being identical but reversed left to right;

FIG. 4 is a front elevational view thereof; and

FIG. 5 is a rear elevation view thereof. 

The ornamental design for a compact oxygen concentrator, as shown and described. 